A rather strange problem since everything used to work up till now ...

All of a sudden, I can't input Japanese characters in KWrite (although the input works in all other applications as far as I know). Does anyone have an idea what the cause might be, or what I should be looking at?

The point is not that I can't see the characters (but e.g. gibberish instead), but that the characters that I type in the input bar are not transfered into KWrite upon commit.